1. Field of the Invention
The present invention relates to safety apparatus. Specifically, the present invention relates to a textile harness restraint worn by an occupant of an aircraft or other vehicle with the purpose of reducing injuries during a survivable crash, especially injuries to the occupant's upper torso and head.
2. Background of the Invention
During a crash, an occupant in a vehicle (aircraft, car, train, etc.) is generally injured due to rapid motion and/or striking the vehicle's interior structure or components. Accordingly, the vehicle's occupant restraint system is a key component in minimizing and preventing such injury. Although occupant restraint systems have improved over the years, conventional seat-mounted harness restraints do not adequately restrain the head and upper torso from forward or lateral displacement in crashes.
Several conventional restraint harness systems are currently used. Each system has one or more lap belts and shoulder straps which fasten directly into a coupling device. Four-point release attachment systems have four connections, two for shoulder straps and two for lap belts. Five-point release attachment systems are four-point release attachment systems which have a crotch strap and a corresponding release. One-point release attachment systems have a lap belt and diagonal shoulder belt.
A primary drawback of conventional systems is that they are subject to user error. This is because a vehicle occupant must adjust any restraint straps and belts manually. Left to his or her own devices, the occupant generally will not tighten the restraint to the point of maximum effectiveness. One reason for this is that doing so overly restricts mobility, and when given the choice, occupants tend to choose mobility over protection. As a result, restraint straps are loose due to the slack left by the occupant. Because the straps are loose, the occupant moves significantly forward and/or upward during a crash. The motion continues until the slack is removed.
Another important drawback of conventional textile harnesses is that they expose a narrow area of the occupant's shoulders and chest to a high concentration of crash force. Distribution of the crash force is a function of occupant loading during a crash. When an occupant loads the harness during a crash, the force is distributed along the strap(s) and imparted to occupant's body at the points of contact. Thus, it is desirable to maximize the strap area that contacts the body. Doing so, disperses the force across a greater portion of the occupant's body, thereby reducing the likelihood of injury to the occupant caused by the restraint harness.
Several inflatable restraint systems are presently under development for aircraft applications. One such system, described in U.S. Pat. No. 5,282,648 (incorporated herein by reference), uses small inflatable bags attached to the shoulder harness straps to remove slack and provide head support. Although this system effectively redistributes crash loads, it requires structure in addition to the harness mechanism. Such additional structure includes pyrotechnic gas generators to inflate the inflatable bags at the time of impact. The inflatable bags remove the undesired slack. However, the additional structure adds significantly to the cost and complexity of the system.
It is desirable to have a restraint harness that considerably reduces the drawbacks of conventional harnesses described above. Moreover, it is desirable if the reduction in limitations does not add significantly to the cost and complexity of the restraint harness by requiring significant structural modifications. Thus, what is required is a restraint harness that reduces occupant-required adjustments, maximizes strap area, and limits occupant motion during a crash.